1. Field of the Invention
The present invention relates to a bookbinding apparatus that coats a collated sheet bundle such as a document with an adhesive, and to an image forming system including the bookbinding apparatus, and more specifically, to a bookbinding apparatus that has a unique sheet bundle process in the case where a job is stopped (discontinued) in a bookbinding process, and to an image forming system including the bookbinding apparatus.
2. Description of the Related Art
In general, there has been widely known an apparatus having a structure in which sheets conveyed from an image forming apparatus or the like are stacked into a bundle, followed by collation of the bundle of the sheets, a spine-stitched end surface of such a sheet bundle is coated with an adhesive, the sheet bundle is then bound with a cover sheet fed from a route different from that for the sheet bundle, and automatically performs a bookbinding design for the bound sheet bundle and cover sheet. In particular, recently, there has been widely used a printing system that, as needs arise, forms an image on the sheets by the image forming apparatus, followed by collation of the sheets, and binds the cover sheet with such a collated sheet bundle, thereby performing a bookbinding finishing for the bound cover sheet and sheet bundle into a book form.
Specifically, for example, as disclosed in Japanese Patent Application Laid-Open No. 2003-292230, the sheets sequentially conveyed from the image forming apparatus are stacked on a tray, followed by collation thereof, the bundle of the sheets thus collated is conveyed to an adhesive coating position, and at this position, the spine-stitched end surface of the sheet bundle is coated with the adhesive. After that, the sheet bundle is bound with the cover sheet fed through another route, and the adhesive solidifies, thereby performing bookbinding for the bound cover sheet and sheet bundle.
Incidentally, in the bookbinding apparatus as described above, for example, in a case where the cover sheet conveyed through the another route than that for the sheet bundle runs out during the bookbinding, a bookbinding process (job) is sometimes stopped at a stage before the sheet bundle is subjected to the bookbinding.
In the above-mentioned conventional bookbinding apparatus, for example, in the case where the bookbinding process is stopped in a state where multiple sheets are discharged to a gathering tray and are collated thereon, the sheets discharged on the gathering tray are sometimes placed in an unbundled manner, so there are problems in that it is difficult to pick up the sheets and in that operability of the bookbinding apparatus is poor.
Further, in the case where the job is stopped at the stage before the sheet bundle reaches the adhesive coating position, the sheet bundle is sometimes in a state of being grasped by grippers and the like. Then, the sheet bundle is fallen into the bookbinding apparatus in the case of performing jam clearance, and in such a way, there is a problem in that operability of the bookbinding apparatus in the jam clearance is also poor. In particular, when a high-temperature adhesive coating portion is located in the vicinity of an operator when the sheet bundle is processed, then a problem occurs on safety of the operator. Accordingly, it is necessary to install parts and devices for hiding the high-temperature adhesive coating portion, leading to such a demerit as complication of a structure.